Work-feed mechanism of sewing-machines



M. T. DENNE. WORK FEED mscmmsm 0F SEWING MACHINES.

. APPLICATION FILED SEPT. 30, 1918. 1 80,888, Patented June 7, 1921.

2 SHEETS-SHEET I.

Mark Thomas Denna M. T. DENNE.

WORK FEED MECHANISM OF sawme MACHlNES.

APPLICATION HLED SEPT. 30, I918.

Patnted June Z, 1921.

2 SHEETS-SHEET 2.

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WORK-FEED MECHANISM OF SEWING-MACHINES.

Specification of Letters Patent.

Patented June 7, 1921.

Original application filed. September 22, 1314, Serial No. 863,025. Divided and this application filed September 3-0, 1918. Serial No. 256,212.

To all whom it may concern:

Be it known that 1, MARK THOMAS Dnnnn, a subject of the King of Great Britain and Ireland, residing at Rushden, Northamptonshire, England, have invented new and useful Improvements in Work-Feed Mechanism of Sewing-Machines, of which the following is a specification.

This invention has reference to improvements in the work-feed mechanism of sewing machines, and more particularly machines of the type known as outsole stitchers used for stitching the outsole to the welt or to the middle sole of boots and shoes and in which a curved needle and a curved awl are employed, and the present application is a division of my application No. 863,025 filed September 22nd, 1914 which matured into Patent No. 1,301,400, dated April 22, 1919.

The features wherein my invention resides will be more particularly hereinafter pointed out and enumerated in the appended claims.

The invention is illustrated in the accompanying drawing in which:

Figure l is a front elevation of my improved awl-feed mechanism, and

Fig. 2 is an end elevation of same, partly in section on the line A.A of Fig. 1.

Fig. 3 is a vertical section of Fig. 1 taken in the axial line of the pin 6.

Inasmuch as my present invention relates solely to the work-feeding mechanism by which the awl operates to feed the work, I have not deemed it necessary to illustrate the complete sewing machine herein, but have confined the illustration to the elements which relate particularly to the invention.

2. Indicates the awl-carrier which may be of usual construction and which is supported on an extension formed on a feed slide 1 which is mounted for reciprocating movement on guides 20 formed on the main frame 22 of the machine. The feed slide 1 is given its reciprocating movement through the medium of a rock-shaft 4 which is journaled in the frame 22 and is provided with a lever 3 that is operated from a suitable cam for oscillating the rock-shaft. This rock-shaft 4 carries at its end a crank arm 40 having a slot or groove 41 formed therein. The feed slide 1 is provided with vertical ways 23 in which is slidably mounted a slide-block 7. This slide-block 7 is carried on a pin 6 which extends through a slot in the feed slide 1 and has on its inner end a square block 5 that fits in the groove 41 of the crank arm 40. When the crank arm 40 is oscillated, the pin '6 will be given a back and forth movement because of the fact that the block 5 carried by the pin is received in the groove 41, and this back-and-forth movement of the pin will be communicated to the feed slide 1 by means of the slide 7.

The rock-shaft 4 has a fixed amount of angular movement imparted to it, and the operative connection between the crank arm 40 and the feed slide is made adjustable so that the fixed oscillating movement of the crank arm can be made to give the feed slide 1 a greater or less reciprocating movement.

The pin 6 has pivotally mounted thereon a lever 10 which is formed at one end with gear teeth 10 that are arranged to mesh with r the teeth of a rack 9. This rack 9 is adjustable vertically in ways 24 formed on the feed slide 1 and it is held in its adjusted position by means of a clamping screw 8. If it is desired to lengthen the feeding movement of the feed-block for the purpose of producing longer stitches, then the screw 8 may be unclamped and the rack, together with the pin 6 and slide 7, may be adjusted vertically to carry the block 5 toward the outer end of the groove 41, and when the desired position has been reached the clamping screw 8 is tightened to lock the rack in proper position. The lever 10 is normally held by friction in the horizontal position shown in full lines, but this lever and the rack 9 provide means by which the length of feed may be adjusted while the machine is running, for it will be observed that if the lever 10 is moved upwardly, as shown by dotted lines,

Fig. 1, such upward movement will operate 9 to raise the pin 6 and thus to carry the block 5 further towardthe outer end of the groove 41. This lever 10 may be manipulated by the operator while the machine is running if desired.

The lever 10 is provided with a stop 27 in the form of a pin or projection which operates in a slot 28 formed in a plate 11 which is carried on the pin 6 and which is retained in adjusted position by a clamping screw 12. This screw 12 is screwed into the block 7 and passes through a slot 29 formed in the plate 11, said slot permitting the plate to be swung about the pin 6 into any adjusted position. When the plate has been properly set, the

lever 10 may be raised until the stop 27- strikes the inner end of the slot 28. V

The portion 26 of the pin 6 on which the block 5 is mounted is eccentric so that by turning the pin a slight adjustment of the feeding movement of the feed slide and awl may be secured.

I claim:

1. In a sewing machine, the combination with a frame, of an aWl-carrying feed-slide slidably mounted thereon and provided with a vertical slot, a rock-shaft journaled in the frame andhaving at its end a crank provided with a slot, a plate slidably mounted in the slot of the slide, a pin carried by said plate and carrying at its end a blockslidably mounted in the slot of the crank arm, a lever pivotally mounted on said pin, and an adjustable fulcrum for the lever mounted on the feed-slide.

2. In a sewing machine, the combination with a frame, of an awl-car'rying feed-slide slidably mounted thereon and provided with a vertical slot, a rock-shaft ournaled in the frame and having at its end a crank provided with a slot, a plate slidably mounted in the slot of the slide, a pin carried by said plate and carrying at its end a block slidably mounted in the slotof the crank arm, a lever pivotally mounted on said pin and provided with gear teeth, and a rack adj ustably secured to the feed slide with which said gear teeth mesh.

In testimony whereof I have signed my 7 name to this specification.

MARK THOMAS DENNE. 

